Theft of cargo carrying vehicles is a serious problem. Many billions of dollars in commercial cargo travel our highways each and every day. The value of the cargo is very enticing to those criminally inclined who profit from theft of such cargo. Notwithstanding numerous efforts to stem the tide of such crimes, the loss of stolen cargo is still a serious problem. The monetary loss of cargo also causes an increase in the price of goods to each and every citizen. Some estimates place the annual loss of cargo by theft in the tens of billions of dollars. More recently, with emphasis on preventing or deterring terrorist activity, it is of paramount importance to prevent theft of tractor trailer rigs carrying sensitive cargo, such as weapons, volatile gases or the like.
Many efforts have been made in the past to stop or curtail cargo thefts, including the addition of guards at truck stops or the adding of guards who ride “shot-gun” on these vehicles. With specific reference to tractor-trailer truck rigs by way of example only and not as a limitation, for which the present invention has specific usefulness, a typical prior art device is commonly referred to as a “king pin lock”. This device comprises a large pin which is inserted into the coupling between the tractor and the trailer in order to prevent a hook-up of a cargo-laden trailer to an outlaw tractor. Another prior art device is referred to as a “glad hand lock”, which prevents hooking up of the air brake lines between the tractor and an outlaw trailer. There are many other similar types of prior art anti-theft devices available, but none of them prevents theft of the tractor itself. If the tractor cannot be moved, then the trailer cannot be decoupled from the tractor, thereby preventing theft of the cargo.
An exemplary prior art device is disclosed in U.S. Pat. No. 5,688,027, entitled CONTROL VALVE LOCK FOR A VEHICLE AIR BRAKE SYSTEM, which issued Nov. 18, 1997 to James J. Johnson. This patent discloses a lock device that is securable to the valve actuating shaft on the dashboard control valve and includes a base member to which is secured a large actuating lever. A lock cylinder extends through a portion of the lever and base member and aligns internal locking cavities between the connecting shaft of the lever and the base member whereby the locking dog of the lock cylinder can engage in the cavities to secure the lever in a retracted position thereby locking the brakes of the vehicle. In order to unlock the brakes, it is necessary to insert a key in the key cylinder to free the lever in order to permit it to be pushed in, whereby the dashboard control valve can supply air to the parking brake cylinder to release the brakes. A large disadvantage of this prior art device is that it is complicated and requires modification of the air brake control mechanism in order to install it on the vehicle.
Another exemplary prior art device is disclosed in U.S. Pat. No. 5,375,916, entitled TRUCK AIR BRAKE LOCKING DEVICE, which issued Dec. 27, 1994, to Bradley W. Cook. This prior art device is directed to a clamp assembly that locks onto the valve knobs of a tractor-trailer rig rendering control of the air brakes inoperable. This device comprises two half bodies connected by a central locking part and at least two side posts, wherein the bodies are placed on the valve knobs, clamped together and locked by means of a lock assembly. A serious problem exists with this device in that a gap exists between the two bodies, which gap is in line with the brake control knobs. Hence, it would be easy for a theft to defeat the purpose of this device.
Yet another prior art device is disclosed in U.S. Pat. No. 5,560,233, entitled AIR BRAKE VALVE SHACKLE, which issued Oct. 1, 1996, to Gerald Watkins. This patent discloses a locking device for air brake valves on vehicles, which comprises releasable elements for engaging an air brake control valve control knob from being pushed inwardly to release the air brakes. The releasable elements are formed identically to one another and, when secured in place allows a gap to exist between the elements in line with the valve control knobs, which could allow one to tamper with the lock and defeat its purpose.
A major problem with the prior art devices discussed above is that they are easily defeated by an industrious theft. That is, there are weaknesses in the design of these devices that would allow a theft to pry open the device or to insert an instrument inside the device and depress the air brake release knobs. Still other of these prior art devices include a lock that could be easily broken. None of the above-cited patents, taken singly or in combination, is seen to describe the device of the present invention as claimed herein.